One of those guns that, if I had been smart when young (as if!)--would have been all I needed. I have a 66-2 that is pretty close to it but just doesn't balance and feel like a 15/67.
When I carried a M15 in the USAF overseas (SEA) I stoked it up with some home brewed 158 gr. SWCHPs and 12 grains #2400. Never touched any of them off but I think they would have been an improvement on the GI load.
NICE little guns. I need one.
Not exactly I.A.W. the treaties of the day, but the VC never worried about that stuff either. Up theirs. And welcome home.